1. Field of the Invention
The present invention relates to a technology for controlling a power converting system, and more particularly, to a technology for controlling the switching of power converters included in a power converting system.
2. Description of the Prior Art
A multilevel converter may be used to convert direct current into alternating current, or alternating current into direct current. The multilevel converter in which a plurality of power converters are connected in series with each other precisely control operating time points or switching time points of the power converters to convert direct current into alternating current, or alternating current into direct current.
The switching of the serially connected power converters is controlled depending on an input waveform, and outputs of the respective power converters are summed up according to the switching time points of the power converters to configure an output waveform. Accordingly, the technology for precisely controlling the switching time points of the respective power converters is emerging as a major issue in the commercialization of the multilevel converter.
With an increase in the number of power converters included in the multilevel converter, a performance improvement such as reduction of high frequency distortion of the output waveform can be made. However, with the increase in the number of power converters, an algorithm for precisely controlling the switching time points of the respective power converters is complicated.